Chapter 17- Regulation of Gene Expression

Question 1

Bacterial Gene Regulation

Answer 1

• constitutive genes
• regulated to meet cells needs
• encode enzymes needed for processes
• enzymes are regulated by pathways they catalyze
• ** bacteria regulate enzyme synthesis differently: varies b/n type+mec, catabolic(degrading) OR anabolic (Syntheic ) pathway

Question 2

Catabolic pathway

Answer 2

• cat enzymes= degrade specific substrate

- >Lactose by beta- galactosidase (first transported by galactidosidase permease)

Question 3

Substrate induction

Answer 3

-> beta-galactosidase only produced when lactose present

Question 4

repression and inhibition

Answer 4

• end product repression: reduced expresion of regulated gene
• repressioin effect on protein synthesis and activity

Question 5

Effecter Molecules

Answer 5

• control enzyme synthesis (induction and repression)
• small orgainc mole
• present in cell or surroundings

Question 6

Lactose Catabolism genes

Answer 6

• operan model: two gene types
  1. gene coding for enzyeume used for lactose uptake and metabolism
  2. regulatory gene : product controls activity of 1st gene